![]() ![]() The Pillars diameter should be at least 18.4 mm to withstand the given loads in the problem statement.įrom fine series of metric threads, let us adopt the threads on pillars as M20 × 1.5 having a major diameter of 20mm and core diameter of 18.16mm from the Design standard book. We know that load on each pillar = (π/4) ( d p) 2 σ t Let us consider there are four pillars and the load is equally shared by these pillars. When the material is being pressed, the pillars will be under direct tension. The main function of the pillars is to support the top plate and to guide the sliding plate. Let us assume the diameter of the pillar is d p The outer diameter of the cylinder is d co= d ci + 2 t = 95 + 2×40 = 175mm 3. Now we need to calculate the outer diameter of the Cylinder. The cylinder is to be made up of 40mm thick. The cylinder is usually made of cast iron for which the tensile stress may be taken as 30 N/mm2.Īccording to Lame’s equation, we know that wall thickness of a cylinder, The Inner diameter of the cylinder is d ci = 95 mm Therefore the inner diameter of the cylinder will beĭ ci= d ro+ Clearance (∴ d ro = Outer diameter of the ram) Let us assume the clearance of 15 mm between the ram and the cylinder bore. Now let us design the Cylinder with the main design parameters of the Cylinder We get the Inner diameter of the ram d ri = 67mmĪlso, we have calculated the outer diameter of the ram is d ro= d r= 80 mm 2. Substituting this value of stress in the above expression, The ram is usually made of mild steel for which the compressive stress (σ c)may be taken as 75 N/mm2. We know that the maximum shear stress is one-half the maximum principal stress (which is compressive), therefore Now according to maximum shear stress theory for ductile materials, maximum shear stress is written as P o= External pressure = p = 16 N/mm 2 …(this values is given in the problem statement) The maximum tangential stress (considering external pressure only) is given asĪnd the maximum radial stress is given as ![]() We have already discussed it in the previous article about the stresses in the thick cylinder, according to Lame’s equation, In case, the ram is made hollow to reduce its weight, then it can be designed as a thick cylinder subjected to external pressure. ![]() Let us say 80mm is the diameter of the Ram. ![]()
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